This FAQ page from the Teacher2Teacher service at The Math Forum @ Drexel contains links to many resources offering ideas for celebrating the 100th Day of School. Resources include T2T discussions, children's literature, teacher resource books, and web sites.

In this 8-lesson unit students use buttons to explore logical and numerical relationships that form the conceptual basis for understanding addition and subtraction operations. Topics include counting, ordinal numbers (and relative position), classification (attributes), relationships between numbers, addition of sets, commutativity of addition, sums to 10, fact families (including subtraction), three models of subtraction ("take away", comparative, missing addend), and bar graphs. Includes student activity sheets and a link to an online graphing applet.

This interactive Flash applet supports the exploration of early number. A child or teacher can place a number of objects on the screen and then move the objects to group them, drag them onto a number line or track, into a hoop to create sets of objects, or into a 10 by 10 grid. This applet lends itself well to group work with a projector. Clicking on the info button allows the user to mouse over items to learn how to use them.

This interactive Flash applet supports the exploration of numbers to 100 by simulating a 100-bead string. A teacher or child can move all or some beads to the left or right to add and subtract. The controls allow users to move beads individually or 10 at a time to model different counting and calculation strategies. Users can hide or show the numbers represented by the beads. This applet lends itself well to use on an interactive white board. A pdf guide to this collection of teaching applets is cataloged separately.

This webpage discusses the extension of children's counting skills beyond 10. It illustrates the difficulties resulting from the irregularity of English number names in the teens as well as the challenge of maintaining one-to-one correspondence with larger numbers. Several teaching strategies and activities are suggested to help students overcome these difficulties.

In this 6-lesson unit, students use dominoes to explore four models of addition: counting, number line, sets, and balanced equations. They learn about the commutative property, the relation between addition and subtraction, the result of adding 0, and the concept of doubles. Students write story problems which involve the operation of addition and begin to memorize the addition facts. They represent addition in pictures. The various models of addition help students develop a rich conceptual schema for addition. Included are a Bibliography of Counting Books, student materials, questions for student and teacher reflection, assessment and extension ideas. [Suggestion: Use the alternate applet, Pan Balance - Numbers, listed as a Related Resource, rather than Pan Balance - Shapes, in Lesson 4.]

This interactive Flash applet provides a customizable set of dominoes that users can manipulate to play games or solve puzzles. It can be used with an interactive whiteboard to facilitate group work. Users can determine the size of a set (up to double-9), remove individual dominoes, rotate and move them, and change their size. The Teachers' Notes page includes a link to page containing domino games and challenges (cataloged separately).

This 37-page pdf provides background information and teaching activities for developing young children's number sense. The document includes instructions and printable materials for using dot cards, five frames, and ten frames.

This interactive Flash applet develops early counting skills (1-10), including one-to-one correspondence and subitizing. A group of dots appears on a card, in progressively higher numbers, and the user types the corresponding numeral. The applet provides help for incorrect answers. Setting options include type of pattern (standard or random), timing (on/off and duration), initial range of numbers displayed, and number of correct answers required for each pattern. [Note: If an error message appears at the end of a round, close the window to return to the applet.]